Education reform must continue despite the efforts of "vested interests" opposed to change, Michael Gove has said.
The Education Secretary declared "a child's education is only ever as good as their teacher", and said the focus will remain on improving the quality of teaching.
Writing in a joint letter with Spain and Portugal's education ministers, published in the Daily Telegraph, Mr Gove said: "Our struggle has not always been easy.
"All of us have been opposed by vested interests determined to hold back reform, insisting that things must stay the same. We understand that change can be difficult. But it must happen."